The invention relates to a circuit arrangement for the protection switching of transmission devices in ring architectures carrying MPLS packets.
A circuit arrangement for the protection switching of transmission devices in ring architectures is known from German patent application DE 197 039 93.6.
This circuit arrangement relates to transmission devices via which information is conducted in accordance with an asynchronous transfer mode (ATM). In this arrangement, a transmission device for the bidirectional transmission of digital signals is provided in which two switching devices acting as terminal stations are connected to one another via a multiplicity of operating links and one protection link. The two terminal stations in each case contain monitoring devices for detecting transmission disturbances. A switching system, which can be controlled by a monitoring device, connects a receiving device to the operating link in a first switching state and to the protection link in a second switching state.
The disadvantageous factor of this circuit arrangement is that it relates exclusively to ATM transmission devices. In the Internet, information is supplied to the receiving subscriber via a multiplicity of network nodes which can be constructed as routers. Between the routers, MPLS networks can be arranged. However, there is no mention whatsoever of MPLS networks in the known circuit arrangement.
The invention relates to a circuit arrangement in such a manner that information which is transmitted in accordance with an Internet protocol can be transmitted with great reliability over a multiplicity of network nodes.
One advantageous embodiment in the invention is that a multiplicity of linear transmission sections formed from MPLS switching devices are joined to form a ring system. In this arrangement, a transmission section is formed by an operating link and/or a protection link. Furthermore, two oppositely directed unidirectional MPLS connections which in each case connect the same MPLS switching devices are logically associated with one another, and operating link and protection link are conducted via different physical routes. The MPLS switching devices are constructed as label switched routers. This is associated with the advantage that in the case of a fault on the operating link, MPLS connections can be maintained efficiently in such evolved ring systems.